Stephen Hales (17 September 1677 – 4 January 1761) was an English clergyman who made major contributions to a range of scientific fields including botany, pneumatic chemistry and physiology. He was the first person to measure blood pressure. He also invented several devices, including a ventilator, a pneumatic trough and a surgical forceps for the removal of bladder stones. In addition to these achievements, he was a philanthropist and wrote a popular tract on alcoholic intemperance.
Life Stephen Hales was born in Bekesbourne, Kent, England. He was the sixth son of Thomas Hales, heir to Baronetcy of Beakesbourne and Brymore, and his wife, Mary (née Wood), and was one of twelve or possibly thirteen children. Thomas Hales (died 1692) predeceased his father, Sir Robert Hales; therefore Sir Robert's grandson, Sir Thomas Hales, 2nd Baronet (Stephen Hales' brother) succeeded to the baronetcy in December 1693. Hales was educated in Kensington and then at Orpington before attending Corpus Christi College, Cambridge (or St Benedict's, as it was then known) in 1696. Although he was an ordinand studying divinity, Hales would have received his degree in the Classics, mathematics, natural sciences and philosophy while in Cambridge. Hales was admitted as a Fellow of Corpus Christi in 1703, the same year as he obtained the degree of Master of Arts, and was ordained as deacon at Bugden, Huntingdonshire. He continued his theological and other studies in Cambridge, where he became friends with William Stukeley who was studying medicine. He attended chemistry lectures by Giovanni Francisco Vigani while at Cambridge. His interest in biology, botany and physiology is presumed to date from that time. In 1709 he was ordained priest at Fulham and on 10 August 1709 he was appointed perpetual curate of the parish of Teddington, Middlesex, and left Cambridge, although he retained his Fellowship until 1718. He became a Bachelor of Divinity in 1711. Hales remained in Teddington for the rest of his life, except for occasional visits to his other parishes. He was an assiduous minister – in addition to parish duties he enlarged and repaired the parish church and commissioned a new water supply for the village – and well regarded although there is some evidence that his experimental work on animal physiology was viewed with misgivings. Thomas Twining included a verse in his poem "The Boat on Hales":
Green Teddington's serene retreat For Philosophic studies meet, Where the good Pastor Stephen Hales Weighed moisture in a pair of scales, To lingering death put Mares and Dogs, And stripped the Skins from living Frogs, Nature, he loved, her Works intent To search or sometimes to torment. In 1718, the poet Alexander Pope, a renowned dog lover, also criticized Hales's work. In conversation with his friend, Joseph Spence, Pope reportedly said of Hales: "He commits most of these barbarities with the thought of its being of use to man. But how do we know that we have a right to kill creatures that we are so little above as dogs, for our curiosity, or even for some use to us?". Pope, however was also a close friend of Hales and considered him the model of the man who loves his God. In 1718 Hales was elected a fellow of the Royal Society and in the same year became rector of Porlock, Somerset, a post he held alongside the curacy of Teddington. In 1720 he married Mary Newce, but she died the following year, probably in childbirth; there were no children and he never remarried. In 1723 he was installed as rector of Farringdon, Hampshire (which he held alongside Teddington by employing a curate in Farringdon). Hales spent his summers there and became a friend of Gilbert White, the naturalist, whose family lived nearby. Hales's fame as a scientist grew from 1718 onwards, and by the mid part of the 18th century he had achieved an international reputation. He was one of the eight Foreign Members of the Royal Academy of Sciences, Paris and was elected a member of the Academy of Sciences of Bologna. He received the Copley Medal in 1739 and also became a public figure as a result of his campaigns against the gin trade and his involvement in the Georgia Trust. He was made a Doctor of Divinity by Oxford University in 1733. In his later years he received frequent visits from Frederick, Prince of Wales and his wife, Princess Augusta of Saxe-Gotha, both of whom were interested in gardening and botany. He gave Princess Augusta advice on the development of Kew Gardens, and in 1751 he was appointed Clerk of the Closet to the Princess Dowager, following the death of Prince Frederick, a post he held until his death.
At the age of seventy Hales was chosen by the president and fellows of the Royal College of Physicians to preach the annual Crounian Sermon in the church of St Mary-le-Bow. He selected his favorite topic – "The Wisdom and Goodness of God in the formation of Man". Hales died in his 84th year at Teddington on 4 January 1761 after a short illness. At his own request he was buried under the tower of the church where he had worked for so many years. A monument to Hales was raised by Princess Augusta in the south transept of Westminster Abbey after his death.
Work Hales is best known for his Statical Essays. The first volume, Vegetable Staticks (1727), contains an account of experiments in plant physiology and chemistry; it was translated into French by Georges-Louis Leclerc, Comte de Buffon in 1735 and into Italian by Maria Angela Ardinghelli in Naples in 1750-1752. The second volume, Haemastaticks (1733), describes experiments on animal physiology including the measurement of the "force of the blood", i.e. blood pressure. Translated and annotated by Ardinghelli in 1756.
Plant physiology and the chemistry of air
… excerpt ends here. Continue reading the full article.
